Conventionally, a container refrigeration apparatus configured to cool the inside of a container used for, e.g., marine transportation has been known as a transport refrigeration apparatus (see, e.g., Patent Document 1).
The container refrigeration apparatus may include a detector configured to detect abnormalities of a motor for driving a compressor and an air blower.
Of the motor abnormalities, occurrence of a lock abnormality and a connection abnormality can be typically determined based on a value for current flowing through the motor. If the motor current value is extremely greater than a rated current value, it is determined that the lock abnormality occurs. On the other hand, if the motor current value is extremely smaller than the rated current value, it is determined that the connection abnormality occurs. Specifically, a current threshold for lock abnormality and a current threshold for connection abnormality are set, and the magnitude of each current threshold and the magnitude of the motor current value are compared with each other to determine occurrence of the abnormality.